Regardless of what form symptoms take (SKIN RASH, tingling around the MOUTH, DIARRHEA), a type I hypersensitivity reaction is a systemic response-it affects and involves the body as a whole.
How to Read Your Eyeglass Prescription. The first step to understanding your eyeglass prescription is knowing what OD and OS mean. They are abbreviations for oculus dexter and oculus sinister, which are Latin terms for right eye and left eye.
OD ADD is the bifocal power for the right eye. OS ADD is the bifocal power for the left eye. *OS stands for Oculum Sinister - Latin for 'left eye Did your optometrist also take a PD measurement? That is the measurement between your pupils. This ensures that the prescription is set in correct spot in your glasses.